Overview of Model 204 parameters
Parameters are program variables that control or describe Model 204. You can set these variables to different values to tailor system performance to the requirements of an installation or user.
Basic parameter types
There are seven types of parameters (see this summary for more information); the three basic types of parameters are:
- System: Controls the operation of Model 204 as a whole and affects all Model 204 users. Normally the system manager sets these parameters during system installation.
- File: Affects the organization or structure of Model 204 files. Normally the file manager sets these parameters when a file is created.
- User: Affects the operation of a particular user’s terminal or the characteristics of system responses towards that user. The system manager sets some user parameters when initializing Model 204. Other parameters, especially those that control displays, can be set by any user.
Group definition parameters, which cannot be specified with these commands, are not included in this chapter. The special group parameters (UPDTFILE, PROCFILE, and BLDGFT) are explained in the description of the CREATE command.
Viewing parameters
You can examine the current settings of one or more parameters at any time during a Model 204 session. As shown in the example below, the VIEW command can display the values of specific parameters or sets of parameters:
VIEW ERMX, PGSEP ERMX 30 MAXIMUM NUMBER OF ERRORS PGSEP 2 LINES BETWEEN PAGES
The DISPLAY command displays sets of file-related parameters. You can change many parameter values with the RESET or UTABLE command. See Assigning values dynamically: resetting.
How and where to set parameters
Parameters can be assigned new values in a variety of ways. This section describes the initial assignment of parameter values at the beginning of a Model 204 session and dynamic reassignment, or resetting, of values later in the session.
This section does not discuss the requirements for the values assigned to the parameters. These requirements are explained in Requirements for parameter values.
Each Model 204 parameter has a default value supplied by the system. While a value might be appropriate for most installations, system managers have the option to change some defaults to more suitable values.
Some parameters cannot be set; these are view-only parameters that provide information about Model 204.
Assigning initial values
Where parameters are initially set depends on the type of parameter and the operating environment. The different methods of initially setting parameters are listed below.